This disclosure relates to a medical device and more specifically to an implantable medical device having an internal processor that executes software.
The medical device industry produces a wide variety of electronic and mechanical devices for treating patient medical conditions. Depending upon medical condition, medical devices can be surgically implanted or connected externally to the patient receiving treatment. Clinicians use medical devices alone or in combination with drug therapies and surgery to treat patient medical conditions. For some medical conditions, medical devices provide the best, and sometimes the only, therapy to restore an individual to a more healthful condition and a fuller life. Many implantable medical devices have an internal processor that executes software.
Implantable medical devices with an internal processor typically include neuro stimulators, pacemakers, defibrillators, drug delivery pumps, and diagnostic recorders. The processor executes software to perform functions that can include telemetry, power management, physiological sensing, data recording, therapy delivery, and therapy measurement. As implantable medical devices have increased in sophistication, the software executed by the internal processor has also increased in complexity, and the task of debugging the software has increased in complexity The internal processor meets these demands while operating under a variety of constraints such as power, size, memory, speed, and the like that limit the processor's ability to perform functions other than those required for normal medical device operation. When the internal processor is tasked to perform functions not required for normal medical device operation such as developmental testing, production conformance testing, diagnostics testing, the internal processor can require a significant amount of time to perform these functions. Previous efforts to perform testing included constructing a laboratory model of the implantable medical device using different components to reduce constraints such as power, size, memory, and speed. Although a laboratory module can simulate testing, there are still differences between performance of the laboratory model and performance of the implantable medical device. The time requirements for the internal processor to perform testing can delay production and require compromises to desirable testing protocols. The results for these constraints can be increased costs, increased production time, discrepancies between laboratory product tests and production product tests, and decreased discretionary testing.
For the foregoing reasons there is a need for an implantable medical device to be configured to perform medical device functions with an internal processor and perform testing and diagnostics in another fashion.
An implantable medical device having a processor may have address and data busses of 8 or 16 bits each. If these busses are to be accessed from an external device, then a corresponding number of contact points and even feed-throughs may be required for the external emulation. What would be desirable is an implantable medical device allowing external emulator control of 8 bit wide (or wider) busses while requiring a much smaller number of contact points and feedthroughs. An implantable medical device supporting external emulation not requiring any additional feedthroughs would also be advantageous.